1. Field of the Invention
The present invention relates to electrical connectors, and more particularly to a land grid array (LGA) connector for electrically connecting an electronic package such as a CPU chip, to a circuit substrate such as a printed circuit board (PCB).
2. Description of the Prior Art
LGA connectors are commonly used in personal computer (PC) systems, for electrically connecting CPU chips to PCBs. This kind of connectors can avoid soldering procedures during being mounted on the PCBs.
FIGS. 4 and 5 show such a conventional LGA connector of this kind for electrically connecting a CPU chip 100 to a PCB (not shown). The LGA connector 8 comprises an insulative housing 82 receiving a plurality of contacts 81 therein, a stiffener 83 attached to the housing 82 and having two locking openings 89, a load plate 84 and a lever 85 pivotally mounted to two opposite sides of the housing 82 respectively. A pair of clasps 87 is formed on one side of the load plate 84. The clasps 87 engage with the locking openings 89 of the stiffener 84, for hinging the load plate 84 to the stiffener 83. A tongue portion 90 extends from a side of the load plate 84 opposite to the clasps 87. The tongue portion 90 comprises a slanted section 902 and an engagement section 904. The lever 86 comprises a locating portion 85 with a cam portion 850.
In use, the CPU chip 100 is disposed on the housing 82. The load plate 84 is pressed down onto the CPU chip 100, pressing portions (not numbered) of the load plate 84 resting on the CPU chip 100. The lever 86 is rotated down from a vertical position to a horizontal position, engaging with the tongue portion 90 of the load plate 84. During the rotation, the cam portion 850 of the lever 86 first presses the slanted section 902 of the tongue portion 90, pushing the load plate 84 sliding toward direction of the side the clasps 87 extending therefrom. Being continued rotating, the cam portion 850 engages with and presses the engagement section 904, pushing the load plate 84 sliding to direction of an opposite side the tongue portion 90 extending therefrom.
Because the load plate 84 compresses the CPU 100, the CPU chip is liable to move horizontally during the load plate 84 sliding. Thus, horizontal displacement of the CPU chip 100 occurs. And this can damage effective electrical connection between the CPU chip 100 and the contacts 81 of the housing 82. Further, the moving of the CPU chip 100 may cause the CPU chip 100 to collide and urge inner surfaces of the housing 82. Accordingly, scraping damage of the inner surfaces of the housing 82 happens. The scraped-away particulates of the housing 82 are prone to drop into the housing 82 and to block up the CPU chip 100 upwardly. This can adversely effect firm electrical connection between the CPU chip 100 and the contacts 81 near the scraped-away particulates. As a result, reliability of the electrical connection between the CPU chip 100 and the contacts 82 of the housing 81 is accordingly decreased.
Therefore, a new land grid array electrical connector which overcomes the above-mentioned disadvantages of the prior art is desired.